Tor, the internet anonymiser, received more than $1.8m in funding from the US government in 2013, even while the NSA was reportedly trying to destroy the network.

According to the Tor Project's latest annual financial statements, the organisation received $1,822,907 from the US government in 2013. The bulk of that came in the form of "pass-through" grants, money which ultimately comes from the US government distributed through some independent third-party.

Formerly known as "the onion router", Tor is software which allows its users to browse the internet anonymously. It works by bouncing connections through encrypted "relays", preventing any eavesdropper from determining what sites a particular user is visiting, or from determining who the users of a particular site actually are. That makes it popular amongst organisations trying to promote freedom of speech in nations like China and Syria – but also popular amongst users trying to evade surveillance in the West.

The two largest single grantors of federal money were SRI international, a non-profit research and development centre that aims to bridge the gap between abstract research and industry, and Internews Network, an international non-profit that funds programmes supporting democracy and human rights. The latter gave $555,413 in funding originally from the US Department of State, while the former gave $830,269 in funding ultimately stemming from the US Department of Defense.

The Tor Project also received direct funding from the National Science Foundation and the US Department of State, totalling $100,325 and $256,900 respectively.

The continued funding of Tor by the American government, including (indirectly) the Department of Defense, stands in stark contrast to the Guardian's revelation in October 2013 that the National Security Agency and GCHQ were attempting to destroy the network. Documents obtained by the Guardian detailed proof-of-concept attacks designed to either bring down the Tor network entirely, or to de-anomymise users.

Despite the NSA's attacks on the service, federal funding of Tor has actually increased year-on-year. In 2012, the organisation only received $1.2m in funding from the US government, none of which was direct.